Material is constantly exposed to a lot of energy by the sun, especially in the high-energy blue and UV, which can lead to significant aging effects. In order to run tests, in addition to the high radiation power (intensity), the spectral distribution (similar to the sun, Sun-Like Spectrum AM1.5) and homogeneous lighting output (area) are important. Integrating sphere light sources are ideally suited as a basic technology here. Of course, temperature management is of the utmost importance in such a system. But also the manageability, i.e. changing the lamp, stepless intensity setting, reference detector for signal monitoring, etc.